lets say i have a 9v adapter that is rated for 300ma and i take the 9v and send it through a opamp buffer:
will that increase the current to a potentially higher MA?
(the context is powering multiple effects units with one 9v tap)
No, not in the way I think you're meaning.
Amplifiers (like your buffer) cannot put out more than their power supply will supply to them. In fact, they can't put out as much as they have fed in from their power supplies. If you mean that the buffer is fed from another, bigger, more current power supply, maybe. But if you're trying to get more than 300ma out of a single 300ma-capable power supply, a buffer won't help.
A quick set of guides that are impressed into every engineer's head are these:
1. It's not possible to produce more energy from any process than is put in either as original energy or energy plus mass converted into energy.
2. Not only that, but there are always some losses which mean you get out LESS energy than you put in to start with.
These are accepted as fundamental laws of the way the universe works.
In regards to natural laws - I guess I was thinking something to the effect that a dam would have on a river.
You can make a buck converter, which gives you more current, but at a lower voltage. So you can take your 300mA 9V supply and get (a bit less than) 600mA at 4.5V
power = voltage * current
and like RG said, you can't pull power up out of nowhere
Quote from: bufferz on October 25, 2013, 06:13:57 PM
In regards to natural laws - I guess I was thinking something to the effect that a dam would have on a river.
A dam on a river stores energy in potential energy and reduces flow (current). In electrical terms, it's much like charging up a cap with a high voltage, low current source.